public class Test01 {


    public class TreeNode {
        int val;
        TreeNode left;
        TreeNode right;

        TreeNode() {
        }

        TreeNode(int val) {
            this.val = val;
        }

        TreeNode(int val, TreeNode left, TreeNode right) {
            this.val = val;
            this.left = left;
            this.right = right;
        }
    }

    class Solution {
        public TreeNode pruneTree(TreeNode root) {
            if (root == null) {
                return null;
            }

            root.left = pruneTree(root.left);
            root.right = pruneTree(root.right);

            if (root.left == null && root.right == null && root.val == 0) {
                root = null;
            }
            return root;
        }
    }

    public static void main(String[] args) {

    }
}
